Author/Authors :
Djimde, Abdoulaye A. Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Ouologuem, Dinkorma T. Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Kone, Cheick O. Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Fofana, Bakary Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Sidibe, Bakary Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Togo, Amadou H. Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Dembele, Demba Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Toure, Sekou Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Koumare, Sekou Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Toure, Ousmane Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Sagara, Issaka Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Toure, Abdoulaye Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Dao, Adama Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali , Doumbo, Ogobara K. Malaria Research and Training Center - Department of Epidemiology of Parasitic Diseases - University of Science - Techniques and Technologies of Bamako - Bamako, Mali
Abstract :
Most malaria-endemic countries use artemisinin-based combination therapy (ACT) as their first-line treatment. ACTs are known to be highly effective on asexual stages of the malaria parasite. Malaria transmission and the spread of resistant parasites depend on the infectivity of gametocytes. The effect of the current ACT regimens on gametocyte infectivity is unclear.
Objectives
This study aimed to determine the infectivity of gametocytes to Anopheles gambiae following ACT treatment in the field.
Methods
During a randomised controlled trial in Bougoula-Hameau, Mali, conducted from July 2005 to July 2007, volunteers with uncomplicated malaria were randomised to receive artemether-lumefantrine, artesunate-amodiaquine, or artesunate-sulfadoxine/pyrimethamine. Volunteers were followed for 28 days, and gametocyte carriage was assessed. Direct skin feeding assays were performed on gametocyte carriers before and after ACT administration.
Results
Following artemether-lumefantrine treatment, gametocyte carriage decreased steadily from Day 0 to Day 21 post-treatment initiation. In contrast, for the artesunate-amodiaquine and artesunate-sulfadoxine/pyrimethamine arms, gametocyte carriage increased on Day 3 and remained constant until Day 7 before decreasing afterward. Mosquito feeding assays showed that artemether-lumefantrine and artesunate-amodiaquine significantly increased gametocyte infectivity to Anopheles gambiae sensu lato (s.l.) (p < 10−4), whereas artesunate-sulfadoxine/pyrimethamine decreased gametocyte infectivity in this setting (p = 0.03).
Conclusion
Different ACT regimens could lead to gametocyte populations with different capacity to infect the Anopheles vector. Frequent assessment of the effect of antimalarials on gametocytogenesis and gametocyte infectivity may be required for the full assessment of treatment efficacy, the potential for spread of drug resistance and malaria transmission in the field.
Keywords :
Differential infectivity , gametocytes , artemisinin-based combination therapy , uncomplicated falciparum malaria
